1. Field of the Invention
This invention is directed to a system and method for utilizing a network of independent telephone companies and other telecommunications service providers to provide centralized, custom subscriber services. More particularly, the network provides a distributed Service Creation Environment whereby participating companies can maintain their own service and subscriber databases and, for larger service providers, a distributed Service Control Point (SCP) system hubbed to the network SCP for redundancy and logistical support.
2. Description of the Related Art
Until the early 1980's, often the only intelligent computer in a telephone system was the Central Office switch (CO). If a service provider, such as an independent telephone company (ITC), wanted to provide its customers with a custom service, such as call waiting, call forwarding, etc. the user had to approach the Central Office Switch vendor for a customized switch. Such customization was extremely expensive, often costing upwards of one million dollars and taking three or more years to implement for a single custom service. Such expenses were justified, since, for a switch vendor to provide such a service, often as many as 20,000 lines or more of custom computer code needed to be integrated with literally millions of lines of code in the switch itself and then extensive testing was required. Needless to say, the demand for new services by ITC's and other service providers was somewhat limited.
In the early 1980's, the Bell companies developed the LIDB system, or Line Information Database for verifying credit card calls and 800 calls. The creation of this system was necessary because the explosion of telecommunications service had created approximately 16,000 Central Office switches in the United States. With the advent of credit card calling and 800 number service, the choice was between maintaining a separate database in each such switch for verifying credit cards, 800 numbers, etc., or providing a central database which was accessible for call credit verification from all of the switches. The LIDB system uses a Service Control Point (SCP) which is associated with and is accessible from each Central Office Switch by interrupting the call in process for a period of a few milliseconds and accessing the SCP via a Common Channel Inter-Office Signalling data link (CCIS). The SCP then queries the central LIDB database for credit verification. Once the caller's credit card, the 800 number destination, etc. is verified, the SCP sends a return message to the switch and the call proceeds normally and the caller is unaware of any interruption.
Building upon the centralized billing verification system of LIDB, the Regional Bell Operating Companies (RBOC's) also started investigating the possibility of expanding the LIDB database to include more sophisticated services which were not switch dependent. A series of iterations of the centralized service concept evolved, including IN-1 or Intelligent Network 1, IN-2, etc. until about 1988, when the need for government dictated services in the Federal Telephone System in the FTS 2000 project acted as a catalyst to cause the creation of the AIN or Advanced Intelligent Network by BellCore and the RBOC's. The AIN system took the SCP of the LIDB system and associated a Service Creation Environment or SCE with it, creating an ISCP or Integrated Service Control Point. With this system, each participating Central Office Service Switching Point Switch (SSP) could provide a large variety of customer services, including, e.g. "dial 0 ", 800 numbers, call forwarding, call waiting, automatic calling number identification, voice mail, etc. by recognizing a service "trigger" during call processing and querying the ISCP for the service information associated with the calling or called number.
One example of the efforts by the RBOC's and BellCore to provide enhanced services to businesses is taught in U.S. Pat. No. 5,247,571 (the '571 patent) to William Kay et al., and entitled "Area Wide Centrex". This patent is directed to a system for using AIN capabilities to extend Centrex-type services to businesses over a wide geographic area encompassing multiple CO's.
In a typical Centrex system, a business, such as a large corporation, is provided specialized calling services to standard telephone lines via a local CO. Such services may include intercom capabilities via 2 or 3 digit extension numbers, call transfer between different users in the business, call forwarding and speed dialling services, among others. With Centrex services provided by the local CO, businesses are spared the considerable expense of setting up and maintaining a Private Branch Exchange (PBX) or Private Automatic Branch Exchange (PABX) network, and any number of standard telephone lines can be associated with the business and provided with the Centrex features.
A problem with the Centrex concept was that a business which had multiple office locations served by different CO's could not be provided with common services encompassing telephone numbers in the various locations. With call forwarding, for example, in an existing Centrex system, one employee who receives a call can switch the call to a second employee's telephone by simply flashing the hookswitch and dialling the second employee's number if the second employee is served by the same CO. Where the second employee is located at an office served by another CO, such call forwarding was impossible.
The '571 patent addressed these problems by employing an SCP which was accessible from multiple CO's via multiple associated Signalling Transfer Points (STP's). With this arrangement, a central database could be maintained at the SCP and lines for a single business but served by multiple CO's could be associated for providing Centrex-type services throughout a wide geographic region (a "wide area"), e.g. the entire state of Virginia.
In the '571 patent and other, similar systems, a number of different triggers were provided for causing the CO to access the SCP, among which were (1) Off-hook Immediate, i.e. the SCP database is queried when the customer first lifts his receiver, for providing dial tone, for example; (2) Off-hook Delay, in which dial tone is provided by the CO but the SCP database is queried after the dialling of the destination number, e.g. 1-800 numbers, etc.; and (3) Dialled number sends to Terminating Trigger, in which an entire destination number is dialled by the subscriber but, when the call reaches a destination CO, a query is triggered which interrupts call processing and queries the SCP as to what the terminating switch is to do with the call, e.g. provide a terminating announcement, forward the call to another number, etc.
The system described in the '571 patent, and others like it, have been developed by the RBOC's and BellCore mainly for RBOC and RBOC associated CO's with a vertical marketing strategy in mind. In other words, the central network service providers wanted to monopolize the provision of services by requiring subscribing companies to access the AIN databases only through the SCP's owned by the networks. Furthermore, the RBOC's and other large service providers wanted to control the creation of services and therefore the charges associated therewith. Thus, in order to allow an independent telephone company (ITC) or other competitive access provider (CAP), such as an independent cellular telephone company, for example, to access the AIN services provided by the RBOC's and others, they must be equipped with a Class 5 switch with the built-in capability to access the AIN SCP's. These sophisticated Class 5 switches are very expensive, typically costing from $200,000 to several million dollars, depending upon the switch capacity. Such a financial burden is too great for many of the smaller ITC's.
Nevertheless, it is the desire of many ITC's and CAP's who are not associated with the RBOC's to provide enhanced customer services and thus to become Telecommunications service providers (SP's). Furthermore, with competition in the telecommunications industry ever increasing, many of these independent companies, even the larger ones already equipped with class 5 switches capable of accessing the RBOC provided services, do not wish to reveal privileged customer information to an RBOC or other large, potentially competitive switching network. With the RBOC network, revealing the customer database is a necessity.
There currently exists a network of ITC's and other, independent service providers, called the Independent Telecommunications Network (ITN). ITN already provides centralized LIDB and billing services to many independent service providers in the network. ITN wishes to provide centralized AIN-type services to its participating companies, but without adopting the vertical marketing strategy of the RBOC system and without compromising the integrity of the subscriber databases owned by the participating companies.
It is clear then, that a need exists for a system and method which would allow an existing network, such as ITN, to provide AIN-type subscriber services to its customers and thus allowing independent ITC's and CAP's and others within its network to become SP's, providing lucrative customer services to their subscribers. Such a system and method should also provide for independent creation of custom services by the participating SP's and allow each SP to establish and maintain their own service and customer databases, including independently creating custom services and establishing charges for each service.